US7749249B2 - Method and device for closing holes in tissue - Google Patents

Abstract

A device for closing holes in tissue is delivered via a catheter to the inside of a body lumen such as a heart. An elastic barbed clip is expanded, pulled into the tissue and released, pulling the tissue with it. The operation is fully reversible.

Description

This application is a CIP of Ser. No. 11/357,011 filed on Feb. 21, 2006 and ABN.

FIELD OF THE INVENTION

The present invention relates to surgery and in particular to closing holes in tissue during minimally invasive surgery. The invention is particularly useful for closing holes left by catheters during percutaneous surgical procedures such as minimally invasive cardiac surgery and other surgeries requiring access to body lumens.

BACKGROUND OF THE INVENTION

More and more surgical procedures are performed percutaneously by the use of catheter-delivered devices. The main advantages are fast patient recovery and lower costs to the medical system. Some tissues, such as muscular tissue or arterial walls, do not seal well and are sometimes subject to blood pressure; therefore they require an immediate hemostatic seal after the surgery. Prior art solutions mainly rely on some form of a plug, such as an expanding foam plug, expanding metal plug or a barbed plug to seal the hole. The main disadvantage of plugs is that in order to form a good seal they are forcing the hole to become larger, rather than the more natural way which is to shrink the hole in order to promote healing. A prior art device operating by shrinking the hole is the Star Closure device sold by Abbott Vascular (www.abbottvasculardevices.com) however this device is only suitable to thin walled body lumens as it relies on folding the tissue. When sealing larger holes in thicker tissue the gripping points for pulling the tissue inwards have to be spread over an area significantly larger than the hole size, similar to what is done in traditional suturing. Attaching the closure device too close to the hole does not allow sufficient forces to be applied, therefore creating a marginal closure.

Another major shortcoming of the Star Closure and other devices is that the operation is not reversible. It is sometimes required to remove the closure, as in the case of bleeding or an additional procedure.

It is therefore desired to provide a hole closure method that provides an immediate liquid and gas tight closure and it can be delivered by a catheter to the inside wall of a body lumen.

It is also desired to provide a closure method suitable for a large range of tissue thicknesses and hole sizes.

It is also desired to be able to test, and if required to remove, the closure.

It further would be desired for the closing device to have permanent elastic properties to accommodate any movement or future changes in the tissue. Furthermore, the gripping area of the closure device has to be significantly larger than the original hole.

SUMMARY OF THE INVENTION

In view of the foregoing, the invention provides a method and device for closing holes in body lumens, and in particular in the heart and blood vessels, achieving an immediate hemostatic seal. The device can be applied via a wide range of catheters sizes to close a wide range of round and elongated holes with performance and reliability of traditional sutures but without requiring access to the tissue, except via the catheter. Furthermore, the device can be removed via the same catheter, and by using the same tools used to install it and can be re-used immediately if so desired. The device has a high degree of elastic compliance allowing a wide accommodation range to changes in the tissue. These and other objects of the present invention are achieved by providing a flexible clip that is temporarily attaches to an insertion tool. The clip has three different positions: a storage position, in which it is folded inside a delivery tube; an expanded position, in which it opens up to reach an area significantly larger than the hole, and a closed position in which elastic forces try to close the clip, pulling the tissue with it to close the hole. The clip has multiple sharp barbs for gripping the tissue and a stem for attaching to the insertion tool, as well as for re-attaching in case removal is required.

Methods for implanting and removal of the device are also provided.

The invention will become apparent by studying the drawings and the detailed description.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view of the invention and the installation tool.

FIG.2-ato FIG.2-fare sectional views showing the steps in installing the device using the installation tool.

FIG. 3 is a perspective “exploded” view of the device.

FIG. 4 is a perspective “exploded” view of an alternate embodiment.

FIG. 5 is an “exploded” view of another alternate embodiment.

FIG.6-ais a perspective view of an alternate embodiment in the relaxed state.

FIG.6-bis a perspective view of the same alternate embodiment in the expanded state.

FIG.7-ais a sectional view of the tool used to install the device embodiment of FIG.6-ain the relaxed state.

FIG.7-bis a sectional view of the tool used to install the device embodiment of FIG.6-ain the expanded state.

FIG.8-ato FIG.8-fare sectional views showing the steps in removing the device,

FIG.9-aand FIG.9-bare perspective views of a device installed on the outside of a catheter.

FIG. 10 is an “exploded” view of the preferred embodiment.

FIG. 11 is a “phantom” view of the actuation mechanism.

FIG.12-ais a perspective view of the preferred embodiment in the fully open position.

FIG.12-bis a perspective view of the preferred embodiment in the retracted position.

FIG.13-ato FIG.13-fare sectional view of the preferred embodiment showing the steps in installing the device.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIG. 1, ahole closure clip3 is inserted into a body lumen such a cavity in the heart viacatheter1.Catheter1 has a seal allowing insertion and removal of tools without much blood loss. This is well known in the art of minimally invasive surgery. When the surgical procedure is completed and hole needs to be closed,tube5 carryingclip3 mounted onrod4 is inserted viacatheter1 through thetissue2. Bothrod4 andtube5 haveflanges7 and8 allowing apulling tool6 to exert a significant pulling force onrod4 relative totube5.Pulling tool6 may be made of plastic or metal, plastic being preferred if tool is to be disposable.Rod4 andtube5 are preferable made of stainless steel andclosure device3 is made of Nitinol, a highly flexible Nickel.Ti˜anium alloy well known in the art of medical devices.Tool6 is similar in construction t the well known clothe-pin. Since the elastic range of Nitinol is about ten times larger than steel, theclip3 can be made to fold into a small diameter tube and expand to grip the tissue over an area significantly larger than the area of the hole, in order to establish reliable closure. Whenclip3 is released it tries to return to its natural (relaxed) shape, which covers a significantly smaller area, pulling the tissue with it and forming an instant hemostatic seal. These steps are shown in FIG.2-ato FIG.2-f.

In FIG.2-athetube5 containing the foldedclip3 mounted onrod4 is inserted viacatheter1 through the wall of thetissue2.Rod4 is pushed forward by finger pressure till it is felt thatclip3 is released from tube5 (or moved till it reaches a pre-determined distance), as shown in FIG.2-b. At this pint it is pulled back and pullingtool6 is installed by sliding it onrod4.Pulling tool6 can be permanently mounted onrod4 or slide in and out via two slots as shown in Figi. The slots rest againstflanges7 and8.Flange7 is rigidly connected torod4 whileflange8 is rigidly connected totube5. Using pullingtool6,rod4 is pulled out a pre-determined amount which forces clip3 to open as shown in FIG.2-c, as it rests against end oftube5. At this point the whole assembly, includingcatheter1, is pulled back to engage the sharp barbs oftool3 intissue2. This is shown in FIG.2-d. An enlarged view ofclip3 is shown inFIG. 3. InFIG. 3,clip3 comprises of multiplesharp barbs11 held by a threadedstem8.Clip3, includingbarbs11 are made of Nitinol wire typically 0.3-0.8 mm in diameter,Stem8 can be made of type316 stainless steel and held to wires by crimping. It contains a threadedportion10 for attaching torod4. The end ofrod4 has amating thread12. Whenclip3 rests on edge oftube5 it can be opened widely by pullingrod4 andbarbs11 can reach over an area having a diameter from 1.5 to over 3 times the diameter of the hole. This is important to achieve proper hemostatic closure. Whenrod4 is detached fromclip3, the natural elasticity pullsbarb11 in the direction shown byarrows13 and the tissue is pulled with them. Centeringferrule19 onrod4 keeps the location ofclip3 centered totube5, therefore centered to hole in tissue. Returning now to FIG.2-e, pullingtool6 is released and removed allowingclip3 to compress the tissue.Rod4 is removed by turningflange7 to unthread rod. After rod is removed the closure can be tested for leaks by leavingtube5 in place. When used in the heart, any imperfection in closure will cause blood to come out oftube5. In such a case theclip3 can be removed and re-installed as shown later on in this disclosure. One verified, bothtube5 andcatheter1 are removed.

FIG. 4 shows an alternate design forclip3. The main differences are that the Nitinol wire is bent into aloop15 to add elasticity and astring14 is used as a method of holdingclip3 totube5. The string can be removed by releasing one end.

FIG. 5 shows another alternate design, preferred when hole is an elongated cut rather than a round hole.Clip3 is bent to havebarbs11 move in parallel rather than radially, as shown byarrows13.Clip3 is placed with the direction ofmotion11 perpendicular to long dimension of hole in tissue.Loops15 are used to add elasticity, as inFIG. 4.

FIG. 6 shows yet another alternate design. Theclip3 can be fabricated from Nitinol sheet, tubing or wire. The preferred way would be laser-cut tubing. FIG.6-ashows the clip in the relaxed state, FIG.6-bshows it in the expanded state. This design is suitable when a large number of barbs111 are desired or for thin˜walled lumens.

The tool used to expand the clip is shown in FIG.7-a(relaxed state) and FIG.7-b(expanded state).Rod4 is equipped with atapered end17 used to expand four pivotingarms16. The sequence of operations is identical to the sequence shown in FIG.2-ato FIG.2-f.

It is desirable to be able to reverse the clip installation and, if needed, remove the clip completely via the same catheter used to install it. The current inventions˜, in all its forms, allows this to be done. Referring now to FIG.8-ato FIG.8-f: the sequence of partial and full removal is shown.

In FIG.8-aadilator18 is used to expand the opening in thetissue2 as well as the surrounding tissue, in order to feedtube5 back into its original position. In FIG.8-bRod4 is inserted intube5 and is attached to clip3 by threading it ontostem8 ofclip3. Centeringferrule19 keepsrod4 aligned withstem8.Tool6 in mounted onrod4 and used to expandslip3 as shown in FIG.8-c. Once expanded, the whole assembly ofcatheter1 andtube5 is pushed forward to removeclip3 fromtissue2, as shown in FIG.8-d. At thispoint clip3 can be re-installed following the steps in FIG.2-cto FIG.2-for removed completely by pulling clip intotube5 as shown in FIG.8-eand FIG.8-f. Onceclip3 is fully insidetube5, it can be easily pulled out byhand using rod4. If desired,clip3 can be re-used immediately by pushing it back intotube5 to assume the position shown in FIG.2-a. When the clip style shown inFIG. 4 is used, the retrieval tool is equipped with a small hook to engage withloop15.

The large elastic range of Nitinol allows full removal without permanently deformingclip3. Because of this large elasticity,clip3 can not be manufactured by cold forming. It has to be held in the relaxed position (shown in FIG.2-b) and heated to about 510 degrees C. for a few minutes. The exact heat treatment details given by the manufacturer of the Nitinol wire have to be carefully followed.

While the invention will work for any dimension of catheter, the preferred range is for catheters with internal diameters of 4 mm to 15 mm. The Nitinol wire diameter is about 0.4 mm for the 4 mm catheter and about 1 mm for the 15 mm catheter. Thethread10 onstem8 is from M1 for the 4 mm catheter to M4 on the 15 mm catheter, M2 being a typical value.Tube5 is made from standard stainless hypodermic tubing. All materials to construct the invention are available from Small Parts Inc (www.smallparts.com). While the detailed description showed a specific embodiment of a clip with four barbs, it is obvious that the inventions covers many other configurations of barbs, made from many materials including materials used to make absorbable sutures and other non-metallic clips. It is also obvious that the invention can be configured to be used on the outside rather than the inside wall of the body lumen by sliding a clip shown in FIG.6-bon the outside oftube5 and expanding it with the method shown in FIG.7-b.

This is shown in FIG.9-a(closed position) and9-b(open position).Tubes4 and5 slide over catheter1 (but can be inside a larger catheter, not shown).Catheter1 penetrates the wall oftissue2 buttube5 only reaches to the outside oftissue2.Clip3 is expanded byarms16 actuated bytaper17 connected totube4. Many alternate expansion mechanisms are well known. Afterclip3 is embedded intissue2,arms16 are retracted andtubes4 and5 are withdrawn.

The preferred embodiment is shown inFIG. 10 as an “exploded” view. This embodiment used similar clips as the previous embodiments and a slightly more complex installation tool. The main additional advantages of this embodiment are:

• • ability to locate the tool within a lumen without use of monitoring such as x-ray or ultrasound.
  • ability to move the tool within the lumen without damage to the surrounding tissue.

To achieve these and further objectives, the sharp barbs of the clip are covered till ready to be embedded, and the tool provides a positive stop to locate the inside wall of the tissue. InFIG. 10clip3 is threaded onto the end ofrod4 viathread12. Atube5, made from extruded plastic or metal, has five holes running through it. Four of the holes are used foractuators20 ending inarms20′. The fifth hole is forrod4.Actuators20 can rotate insidetube5 approximately 180 degrees, opening andclosing clip3.Actuators20 engage in correspondingslots22 insleeve21, which is free to rotate overshaft23 which is clamped toextension5′ oftube5.Rod4 terminates in asection4′ resting ondisc27. By rotatingdisc27 relative toshaft23,disc27 is moved axially away fromshaft23. This is achieved viainclined planes25 and26 but can be achieved by any one of the well known mechanisms converting rotary to linear motion such as threads, cams etc. Whendisc27 is moved axially, it pullsrod4 with it, causingclip3 to slide overarms20′ and expand further. In operation, the tool is held bysleeve21 andring24 is rotated to causetune5 to rotate. Since ends ofactuators20 are inslots22,rotating tube5 will causeactuators20 to rotate and expandclip3. After tool is in position,disc27 is rotated to pull clip overarms20′ and embed barbs in tissue, followed by releasing the tool by turningend4′ ofrod4 to release tool from clip.

FIG. 11 is an enlarged view of both ends ofactuators20. At the end of eacharm20′ there is arecess28 into whichbarbed tip11 ofclip3 fits. This provides a smooth outside surface till the barbs are exposed, and allows the tool to be moved inside a body lumen without damage. For example, when the device is used inside the heart, it is imperative to avoid snagging or damaging any one of the many cords attached to the valves.Clip3 is attached torod4 via athread8 at center of clip.

FIG.12-ais a close-up of the mounted clip in the expanded position while FIG.12-bshows the retracted position. Each one ofarms20′ is semi-circular, with an outside diameter approximately equal that oftube5. The holes intube5 act as the pivot points for arms. At. the outside edge of eacharm20′ there is arecess28 to holdtip11 ofclip3. In the retracted position thearms20′ fold into a circle, overlapping each other.Clip3 is still resting inrecesses28 ofarms20′. Clearly the semi-circles20′ are also bent towardsthread8, in order to allow them to fold partially over each other, in a manner resembling a four-start thread. The amount of axial forward bending is approximately equal to twice the diameter of the wire used to makeactuator20.

By the way of example,tube4 is extruded plastic with a diameter of 4 to 8 mm.Actuators20 are made of stainless steel wire having a diameter of 1.2-1.6 mm.Clip3 is made of 0.3-0.5 mm thick Nitinol sheet or 0.6-0.9 Nitinol wire, as shown inFIG. 3.

FIG. 13 shows the steps in using the device. It is inserted viacatheter1 as shown in FIG.13-a.Clip3 is expanded by rotatingring24. The expandedarms20′ provide a reference surface to locate the inner wall oftissue2 without radiological means.Catheter1 is pulled backwards tillarms20′ stop attissue2, as shown in FIG.13-c. Barbs ofclip3 are exposed by rotatingdisc27 as shown in FIG.13-d, and are embedded intotissue2. In FIG.13-e,ring24 is further turned to fold thearms20′ into the retracted position while embeddingclip3 deeper intissue2, since rotatingdisc24 both folds the arms and pulls onrod4. Afterclip3 is fully embedded intissue rod4 is turned to releaseclip3 fromtool5. As with the other versions of the invention, the operation is reversible by re-attaching tool to clip. Note thatring24 is turned to activate tool rather than bushing21, sinceclip3 needs to remain stationary relative totissue2 once it is embedded.

While the examples used an elastic clip, it is obvious that the invention can be practiced with a non-elastic deformable clip. By the way of example, the clip shown inFIG. 6 can be made of annealed stainless steel. The installation tools have to be slightly modified to be able to apply both tension and compression to the clip. Such a modification is shown inFIG. 7, whereinarm16 has abent tip16′ holdingclip3 from both sides. The clip can be deformed plastically from the shape shown in FIG.6-ato the shape in FIG.6-b, embedded intissue2 and deformed plastically back to the shape of FIG.6-a. After thattool5 is pushed forward to disengage from clip,arms16 retracted and tool pulled out ofcatheter1. The words “clip” and “barb” should be interpreted in a broad sense. Any part left behind in the tissue is considered a clip, regardless of actual shape or material. Any part of the clip used for attachment to the tissue is considered a “barb”, regardless of shape, sharpness, material etc. By the way of example, in the context of this invention, an adhesive patch that can be placed over the hole from the inside and pull the hole to close is considered a clip and the adhesive is considered a barb.

Claims (21)

1. A medical device, comprising:

an elongated tool having at least one actuator, at least a portion of the at least one actuator proximate a distal end of the elongated tool and receivable through an opening in tissue from a first side of the tissue to a second side of the tissue, the at least one actuator operable from a proximate end of the elongated tool to embed a plurality of tissue piercing tips of a clip from the second side of the tissue to seal the opening in the tissue, each of the plurality of tissue piercing tips of the clip protected after the plurality of tissue piercing tips have been expanded to encompass the opening in the tissue, and the tissue piercing tips unprotected as part of embedding the tissue piercing tips in the tissue.

2. The medical device ofclaim 1 wherein the elongated tool further comprises:

an elongated tube having at least one longitudinal passageway extending therethrough; and

a rod received through the passageway of the elongated flexible tube for rotational and translational movement with respect thereto, the rod having a distal end including an engagement member operable to selectively physically engage and disengage at least a portion of the clip.

3. The medical device ofclaim 1 wherein the elongated tube has a plurality of longitudinal passageways extending therethrough that each receive a respective one of the plurality of actuators for rotation therein, in addition to the longitudinal passageway that received the rod.

4. The medical device ofclaim 2 wherein the elongated tool further comprises:

a sleeve received about the rod to allow rotation and translation of the rod through the sleeve, the sleeve having a plurality of slots, each of the slots of the sleeve sized and dimensioned to engage a respective one of the at least one actuator to selectively rotate the at least one actuator.

5. The medical device ofclaim 4 wherein rotation of the actuators rotates the piercing tips of the clip into an overlapping relation with adjacent ones of the piercing tips in a retracted configuration.

6. The medical device ofclaim 5 wherein the elongated tool further comprises:

a tube extension physically coupled to the tube to move therewith;

a shaft physically coupled to the tube extension to move therewith;

a ring physically coupled to the shaft to move therewith; and

a disc physically coupled to the rod to move therewith, the disc further coupled to transform a rotational motion of the disc into a translational motion of the shaft.

7. The medical device ofclaim 6 wherein at least one of the disc and the ring includes an inclined surface that transforms the rotational motion of the disc into the translational motion of the shaft.

8. The medical device ofclaim 6 wherein the proximate end of the rod includes a knob portion to the rod to be grasped and rotated.

9. The medical device ofclaim 2, further comprising:

the clip having the plurality of resilient tissue piercing tips, the clip further including a stem from which the resilient tissue piercing tips extend, the stem including an engagement member that is complementary to the engagement member of the rod.

10. The medical device ofclaim 9 wherein the engagement member of the stem is a threaded portion and the engagement member of the rod is a threaded portion.

11. The medical device ofclaim 9 wherein the stem and the tissue piercing comprise a single unitary structure.

12. The medical device ofclaim 9 wherein the plurality of tissue piercing tips of the clip are comprised of Nitinol.

13. The medical device ofclaim 1 wherein each of the at least one actuator has at least one recess to protectively receive a respective one of the tissue piercing tips of the clip prior to embedding of the clip in the tissue.

14. The medical device ofclaim 2 wherein the tissue piercing tips of the clip embed in the tissue from the second side in response to the rod being pulled.

15. The medical device ofclaim 9 wherein the engagement member of the rod is configured to selectively detached the clip therefrom after the clip has been embedded in the tissue from the second side and to reattach to the clip thereto after the clip has been detached therefrom.

16. The medical device ofclaim 15 wherein the tissue piercing tips of the clip are removed from the second side of the tissue in response to the rod being pushed.

17. The medical device ofclaim 15 wherein the at least one actuator protectively receives the tissue piercing tips of the clip after the clip has been reattached to the engagement member of the rod.

18. The medical device ofclaim 1 wherein the at least one actuator includes at least three actuators that are configured to provide a tactile feedback through the elongated tool in response to physically contacting the second side of the tissue when the at least three actuators are positioned to embed the tissue piercing tips of the clip in the tissue from the second side.

19. A medical device, comprising:

an elongated tool having a proximate end and a distal end, at least the distal end receivable internally in a body; and

at least one actuator having at least one arm located at least proximate the distal end of the elongated tool, which at least one arm protectively retains a respective one of each of a plurality of tissue piercing tips of a clip, used to close a hole in the tissue, until the tissue piercing tips start to pierce the tissue at locations encompassing the hole in the tissue.

20. The medical device ofclaim 19 wherein at least a portion of the at least one actuator is receivable through the hole to be closed in tissue from a first side of the tissue to a second side of the tissue, the at least one arm of the actuator configured to hold the clip such that the tissue piercing tips face the tissue from the second side when the at least a portion of the at least one actuator is received through the opening from the first side.

21. The medical device ofclaim 19 wherein the elongated tool comprises an elongated tube having at least one longitudinal passageway extending therethrough and the at least one actuator includes a plurality of actuators each having a respective one of the at least one arm.

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